412 QUARTERLY CHRONICLE OF MICROSCOPICAL^SCIENCE. 



systems anastomose with each other in the ligaments of the 

 hmg, and finally enter the bronchial lymphatic glands. 



The second portion of Klein's paper is occupied by a 

 description of the pathological changes which occur in arti- 

 ficial tuberculosis in animals, of which we can only give a 

 very short account. The first structural changes which 

 appear in the guinea-pig's lung consist in the appearance of 

 perivascular lymphatic nodules and cords. These commence 

 in the ultimate branches of the pulmonary artery, whose 

 endothelium germinates until the lumen of the vessels is 

 nearly blocked by its products; the lymphatics become con- 

 verted into adenoid tissue, which grows from the endothelium 

 both internally (endolymphangial) and externally (peri- 

 lymphangial). These perivascular lymphatic (tubercular) 

 cords spread both along the lymphatics to the larger branches 

 and also towards the interalveolar branched cells. The 

 capillaries of the affected alveoli then become converted into 

 solid nucleated bands and threads, which are continuous 

 with the surrounding reticulum. Secondary to the above 

 process, there is a thickening of the alveolar septa, and a 

 proliferation of the epithelium filling the alveoli, often inter- 

 mixed with lymphoid corpuscles. Sometimes the enlarged 

 epithelial cells become fused into one multinuclear " giant- 

 cell." When this is the case the giant-cells gradually 

 become changed into a fibrillated tissue with few cells, which 

 rapidly spreads, and finally undergoes first a fibrous, then a 

 cheesy degeneration. The adenoid tissue of the perivascular 

 cords never degenerates. The secondary process passes from 

 the infundibula to the bronchi, whose epithelium proliferates 

 abundantly, while the branched cells of the mucosa become 

 converted into adenoid tissue. The process above described 

 takes place in man in inverted order, i. e. the first changes 

 are seen in the alveoli and interalveolar septa, and these 

 changes are followed by the appearance of perivascular 

 cords. 



9. Lymphatics of the Thyroid. — J. Nawalichin (of Kasan) 

 in ' Pfliiger's Archiv,' vol. iii ; abstract in ' London Medical 

 Record,' 1874, p. 262. 



10. On the Cartilages and Synovial Membranes of the 

 Joints. — Keyher (' Journ. of Anat. and Physiol.,' May, 1874, 

 p. 261) investigated the formation and development of the 

 so-called " marginal zone" of the synovial membrane, i. e. 

 the portion which extends over those parts of the articular 

 surfaces which are not ordinarily in contact, the question 

 being whether this is an ingrowth from the synovial mem- 

 brane or not. For this purpose the joints of embryos and 



